CN runs a small local job, usually powered by a single switcher or GP40 model. Longest train I've seen was 26 cars. The last time I saw the crew working the job they were using a Dash 8 or Dash 9, I think a Dash 9 the radiator section looked a tad bigger. Today they were using from what I can tell and SD70I or SD75I, numbered in the low 5900's.
Is this a current trend with CN or other railroads?
I don't think it's a current trend.
Among the photos in Norfolk & Western's Magnificent Mallets, which is full of Y-class locos pulling trains that stretch from here to next week, is one photo where the tender of 2142 is separated from the caboose by a whole six cars - two of which are empty bulkhead flats.
The photo was taken in September of 1958, by which time most of N&W's older steam had been scrapped. Why they used a coal-burning articulated and not a 4-axle diesel on a mainline local is a good question.
Chuck (Modeling Central Japan in September, 1964)
Possibly. It does seem that most of the locomotives built today, with the exception of the Gensets, are big road diesels. Very few class one railroads even use switchers anymore. One size fits all?
For most railroads, it has historically more sense to use downgraded road locomotives as switchers instead of engines designed for the purpose. A few years ago, writers were predicting the demise of the switcher.
But then some new exhaust emissions regulations were announced for switchers. These regulations will require either retrofitting downgraded engines, or the production of new engines.
I think we have now reached the point where road engines are going to be too big to be downgraded, and the railroads are going to have to think about building new engines that can be used for switching and local work.
Dan
Not necessarily a new trend, as the mention of N&W big steam relates.
I was quite surprised back in March of 1976 when I lived in Lawrence, Kansas to see Union Pacific DDA40X #6909 in local service, setting out a couple cars there in Lawrence. This is likely not the best in terms of crew visibility or fuel efficiency, but it happens.
Bill
Sometimes it's a matter of using what's available in the engine house that's running.
__________________________________________________________________
Mike Kieran
Port Able Railway
I just do what the majority of the voices in my head vote on.
Track condition is also a factor.Some industries/customers just do not have good enough track to handle the 6 axles.Most railroads have these restrictions listed in the timetable pages.I can also say that some of the track is also bad for the 4 axles too.Sometimes railroads will try the 6 axles at small industries and siding and find out the hard way,resulting in a derailment Dave
Did you see it go both ways? There could have been a slew of cars farther down the line to justify the engine or it could have been all that was available also.
quite often locomotives which had just come out of the shops from an overhaul would be placed in local service to be "broken in" again. so you would sometimes see passenger locos or bigger than needed freight locos on a local if they needed breaking in.
Cotton Belt operator Terry Kirkland observed a rare occurance on Saturday July 20, 1974 with a local train called the Greenville Dodger. The previous day's Dodger had left Commerce, TEXAS with SP GP9E #3732 and gone over to Greenville to switch industry and possibly interchange with KCS and MKT. But that Dodger never came home to Commerce Yard. It stayed over in Greenville. Saturday's southbound Dodger left Commerce with SP SD45 #8886 and seven cars. The northbound move of the Dodger from Greenville was called X-SP3732-N. It musthave kept on going North, maybe they switched Sulphur Springs. There is no cluein Terry's notes as to why there were 49 cars out of Greenville that day. Obviously toomany cars for the GP9 to handle the previous day and the reason for the SD45 onthe Dodger. It is possible that heavy production from one of the mills was allshipped out on one day or that heavy interchange from KCS and or MKT caused thisamount of cars to be ready for movement on the same day. An SD45 in local service on the Cotton Belt was a rarity.SaturdayJuly 20, 1974Commerce, Texas trains as recorded by operator Terry Kirkland17 (SSW 9272) SD45T-2 U33C 40 140 am18 (SP 8889) 2 SD45 GP9 61 600 pm318 (SP 8652) U33C 2 SD45 56 750 amGVDS (SP 8886) SD45 7 1120 amX-SP 3732-N GP9 SD45 49 250 pm343 (SSW 9157) SD45T-2 2 U33C 78 605 pm
DavidP Track condition is also a factor.Some industries/customers just do not have good enough track to handle the 6 axles.Most railroads have these restrictions listed in the timetable pages.I can also say that some of the track is also bad for the 4 axles too.Sometimes railroads will try the 6 axles at small industries and siding and find out the hard way,resulting in a derailment Dave
David,
A six axle is sometimes the better choice for track with lighter rail, or poor condition track. A six axle locomotive is heavier than a four axle, but in the same series (GP9/SD9, GP35/SD35 etc) the six axle will have a Lighter AXLE LOADING, thus making it useful, where the similar four axle may have to heavy of an axle loading for a particular stretch of track.
This is also the reason for the A-1-A trucks of EMD's "E" series units, and Alco's "PA" series locomotives. On the E units and PA's they only had two powered axles per truck, the center axles were idlers, they were just there to disperse the weight of the locomotive over more axles to keep the axle loadings within an acceptable range.
Doug
May your flanges always stay BETWEEN the rails
BerkshireSteam CN runs a small local job, usually powered by a single switcher or GP40 model. Longest train I've seen was 26 cars. The last time I saw the crew working the job they were using a Dash 8 or Dash 9, I think a Dash 9 the radiator section looked a tad bigger. Today they were using from what I can tell and SD70I or SD75I, numbered in the low 5900's. Is this a current trend with CN or other railroads?
The track is off old GB & W mainline.All right-of-way, including industry spurs, is in good shape.
Re six-axle engines, some manufacturers offered road switchers that railroads could choose to order with B trucks (two axles, all powered), C trucks (three axles, all powered) or A-1-A with a middle idler so that they could fine-tune it to their conditions.
Note that passenger engines had A-1-A trucks less as a matter of distributing weight, since they tended to be purchased for mainline "top of the line" passenger trains, but because the idler truck allowed for a smoother ride at high speed.
Back to the original question. grades can affect what power is used too. Even a short section of grade might require a large engine to pull a short train that otherwise could be pulled by a much lighter engine on level track. I recall that GN had some iron ore mine branches where a Mallet would have to be used to pull 20-30 ore cars because of the roller coaster grades between the marshalling yard and the mining co. yard.
How 'bout this
http://history.nevadanorthernrailway.net/galleries/action/NN%20401%20action%20overhead.jpg
SD-7 with three cars!
sfb
challenger3980 A six axle is sometimes the better choice for track with lighter rail, or poor condition track. A six axle locomotive is heavier than a four axle, but in the same series (GP9/SD9, GP35/SD35 etc) the six axle will have a Lighter AXLE LOADING, thus making it useful, where the similar four axle may have to heavy of an axle loading for a particular stretch of track. Doug
The current practice is to have pretty much equal axle loading between 4 and 6 axle engines. This is pretty much the same axle loading as a loaded 263k car these days, around 66,000 pounds per axle. This gives 6 axle weights around 394,000 lbs. Most newer ones are heavier, 412,000 pounds or more, 70k per axle.
The rigid wheelbase is the key now between an engine going into a spur track or not. 4-axle engine rigid wheelbase is 9 foot, or 9 foot 4 inches. 6-axle rigid is 13 foot or more. If the ties are poor, rails spread, wide gauge, and down you go.
The tracks are getting upgraded to handle the heavier cars. If not upgraded, the railroad should refuse service after derailing a time or two.
CN often uses whatever power is laying around. With more new units coming online, the SD70-75Is are starting to pick up local work. These units have rear ditch lights, and a speedometer in the back wall of the cab, so they are a bit easier to run backwards. It also might be a case of the GP not being big enough to handle the work load, and assigning a SD instead of two GPs saves fuel money, and so forth. The EMD radial truck might allow these to get into places formerly off-limits to 6-axle power as well.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
challenger3980 DavidP: Track condition is also a factor.Some industries/customers just do not have good enough track to handle the 6 axles.Most railroads have these restrictions listed in the timetable pages.I can also say that some of the track is also bad for the 4 axles too.Sometimes railroads will try the 6 axles at small industries and siding and find out the hard way,resulting in a derailment Dave David, A six axle is sometimes the better choice for track with lighter rail, or poor condition track. A six axle locomotive is heavier than a four axle, but in the same series (GP9/SD9, GP35/SD35 etc) the six axle will have a Lighter AXLE LOADING, thus making it useful, where the similar four axle may have to heavy of an axle loading for a particular stretch of track. This is also the reason for the A-1-A trucks of EMD's "E" series units, and Alco's "PA" series locomotives. On the E units and PA's they only had two powered axles per truck, the center axles were idlers, they were just there to disperse the weight of the locomotive over more axles to keep the axle loadings within an acceptable range. Doug
DavidP: Track condition is also a factor.Some industries/customers just do not have good enough track to handle the 6 axles.Most railroads have these restrictions listed in the timetable pages.I can also say that some of the track is also bad for the 4 axles too.Sometimes railroads will try the 6 axles at small industries and siding and find out the hard way,resulting in a derailment Dave
On CN Murray Bay Subdivision, they used around the 60's Alco 3-axles engine because the track wasn't stable enough (most of the roadbed is built directly in St. Lawrence River's shore. I think they were a rare animal, something like RSC-24.
Matt
Proudly modelling the Quebec Railway Light & Power Co since 1997.
http://www.hedley-junction.blogspot.com
http://www.harlem-station.blogspot.com